Chronic pulmonary aspergillosis (CPA) is a chronic progressive infection that destroys lung tissue in non-immunocompromised patients. Contemporary series suggest 50-85% 5-year mortality, with few prognostic factors identified.A cohort of 387 CPA patients referred to the UK's National Aspergillosis Centre from 1992 to June 2012 was studied until June 2015. The impact of objective and subjective variables including age, sex, previous pulmonary conditions, dyspnoea score, quality of life, serum albumin and C-reactive protein and radiological appearances were assessed using Kaplan-Meier curves, log rank tests and Cox proportional hazards modelling. In samples of patients, retrospective review of time from likely onset of CPA to referral and cause of death were also investigated.Survival was 86%, 62% and 47% at 1, 5 and 10 years, respectively. Increased mortality was associated with nontuberculous mycobacterial infection (hazard ratio 2.07, 95% CI 1.22-3.52; p<0.001) and chronic obstructive pulmonary disease (1.57, 1.05-2.36; p=0.029) as well as higher age (1.053, 1.03-1.07 per year; p<0.001), lower albumin (0.92, 0.87-0.96 per g·L), lower activity (1.021, 1.01-1.03 per point increase in St George's Respiratory Questionnaire activity domain; p<0.001) and having one, and especially, bilateral aspergillomas (p<0.001).Several factors impact on mortality of CPA, and can be evaluated as tools to assess CPA prognosis.
The human fungal pathogen is the major etiological agent of vulvovaginal candidiasis (VVC). Despite this fact, other non- (NAC) species have frequently been reported as well. Despite their presence in the vaginal environment, little is known about their capacity to elicit immune responses classically associated with -mediated immunopathology, including neutrophil recruitment and pro-inflammatory cytokine signaling. Therefore, using a combination of in vitro and in vivo approaches, we undertook a comparative analysis to determine whether a representative panel of NAC species could colonize, induce immunopathological markers, or cause damage at the vaginal mucosa. Using a murine model of VVC, was found to induce robust immunopathology (neutrophils, IL-1β) and elicit mucosal damage. However, all NAC species tested (including ,, ,, ,) induced significantly less damage and neutrophil recruitment, despite achieving similar early colonization levels as These results largely correlated with notable lack of the NAC species ( and included) to form hyphae both in vitro and in vivo. Furthermore, both and induced significantly less expression of the gene encoding for Candidalysin, a key fungal virulence determinant driving VVC immunopathology. In order to determine the relative capacity of these species to elicit inflammasome-dependent IL-1β release, both WT and NLRP3-/- THP-1 cells were challenged in vitro. While most species tested elicited only modest amounts of IL-1β, challenge with led to significantly elevated levels that were largely NLRP3-dependent. Collectively, our findings demonstrate that although NAC species are increasingly reported as causative agents of VVC, appears to be exceedingly vaginopathogenic, exhibiting robust immunopathology, hypha formation and Candidalysin expression. Thus, this study provides mechanistic insight as to why is overwhelmingly the major pathogen reported during VVC.
Vulvovaginal candidiasis (VVC), caused primarily by the human fungal pathogen Candida albicans, results in significant quality-of-life issues for women worldwide. Candidalysin, a toxin derived from a polypeptide (Ece1p) encoded by the ECE1 gene, plays a crucial role in driving immunopathology at the vaginal mucosa. This study aimed to determine if expression and/or processing of Ece1p differs across C. albicans isolates and whether this partly underlies differential pathogenicity observed clinically. Using a targeted sequencing approach, we determined that isolate 529L harbors a similarly expressed, yet distinct Ece1p isoform variant that encodes for a predicted functional candidalysin; this isoform was conserved amongst a collection of clinical isolates. Expression of the ECE1 open reading frame (ORF) from 529L in an SC5314-derived ece1Δ/Δ strain resulted in significantly reduced vaginopathogenicity as compared to an isogenic control expressing a wild-type (WT) ECE1 allele. However, in vitro challenge of vaginal epithelial cells with synthetic candidalysin demonstrated similar toxigenic activity amongst SC5314 and 529L isoforms. Creation of an isogenic panel of chimeric strains harboring swapped Ece1p peptides or HiBiT tags revealed reduced secretion with the ORF from 529L that was associated with reduced virulence. A genetic survey of 78 clinical isolates demonstrated a conserved pattern between Ece1p P2 and P3 sequences, suggesting that substrate specificity around Kex2p-mediated KR cleavage sites involved in protein processing may contribute to differential pathogenicity amongst clinical isolates. Therefore, we present a new mechanism for attenuation of C. albicans virulence at the ECE1 locus.
Repurposing of currently approved medications is an attractive option for the development of novel treatment strategies against physiological and infectious diseases. The antidiabetic sulfonylurea glyburide has demonstrated off-target capacity to inhibit activation of the NLRP3 inflammasome in a variety of disease models, including vaginal candidiasis, caused primarily by the fungal pathogen Candida albicans. Therefore, we sought to determine which of the currently approved sulfonylurea drugs prevent the release of interleukin 1β (IL-1β), a major inflammasome effector, during C. albicans challenge of the human macrophage-like THP1 cell line. Findings revealed that the second-generation antidiabetics (glyburide, glisoxepide, gliquidone, and glimepiride), which exhibit greater antidiabetic efficacy than prior iterations, demonstrated anti-inflammatory effects with various degrees of potency as determined by calculation of 50% inhibitory concentrations (IC50s). These same compounds were also effective in reducing IL-1β release during noninfectious inflammasome activation (e.g., induced by lipopolysaccharide [LPS] plus ATP), suggesting that their anti-inflammatory activity is not specific to C. albicans challenge. Moreover, treatment with sulfonylurea drugs did not impact C. albicans growth and filamentation or THP1 viability. Finally, the use of ECE1 and Candidalysin deletion mutants, along with isogenic NLRP3−/− cells, demonstrated that both Candidalysin and NLRP3 are required for IL-1β secretion, further confirming that sulfonylureas suppress inflammasome signaling. Moreover, challenge of THP1 cells with synthetic Candidalysin peptide demonstrated that this toxin is sufficient to activate the inflammasome. Treatment with the experimental inflammasome inhibitor MCC950 led to similar blockade of IL-1β release, suggesting that Candidalysin-mediated inflammasome activation can be inhibited independently of potassium efflux. Together, these results demonstrate that the second-generation antidiabetic sulfonylureas retain anti-inflammatory activity and may be considered for repurposing against immunopathological diseases, including vaginal candidiasis.
Although considered effective treatment for many yeast fungi, the therapeutic efficacy of the echinocandin class of antifungals for invasive aspergillosis (IA) is limited. Recent studies suggest intense kinase- and phosphatase-mediated echinocandin adaptation in A. fumigatus. To identify A. fumigatus protein kinases required for survival under echinocandin stress, we employed CRISPR/Cas9-mediated gene targeting to generate a protein kinase disruption mutant library in a wild type genetic background. Cell wall and echinocandin stress screening of the 118 disruption mutants comprising the library identified only five protein kinase disruption mutants displaying greater than 4-fold decreased echinocandin minimum effective concentrations (MEC) compared to the parental strain. Two of these mutated genes, the previously uncharacterized A. fumigatus sepL and sidB genes, were predicted to encode protein kinases functioning as core components of the Septation Initiation Network (SIN), a tripartite kinase cascade that is necessary for septation in fungi. As the A. fumigatus SIN is completely uncharacterized, we sought to explore these network components as effectors of echinocandin stress survival. Our data show that mutation of any single SIN kinase gene caused complete loss of hyphal septation and increased susceptibility to cell wall stress, as well as widespread hyphal damage and loss of viability in response to echinocandin stress. Strikingly, mutation of each SIN kinase gene also resulted in a profound loss of virulence characterized by lack of tissue invasive growth. Through the deletion of multiple novel regulators of hyphal septation, we show that the non-invasive growth phenotype is not SIN-kinase dependent, but likely due to hyphal septation deficiency. Finally, we also find that echinocandin therapy is highly effective at eliminating residual tissue burden in mice infected with an aseptate strain of A. fumigatus. Together, our findings suggest that inhibitors of septation could enhance echinocandin-mediated killing while simultaneously limiting the invasive potential of A. fumigatus hyphae.
Propafenone, a class Ic antiarrythmic drug, inhibits growth of cultured Plasmodium falciparum. While the drug’s potency is significant, further development of propafenone as an antimalarial would require divorcing the antimalarial and cardiac activities as well as improving the pharmacokinetic profile of the drug. A small array of propafenone analogs was designed and synthesized to address the cardiac ion channel and PK liabilities. Testing of this array revealed potent inhibitors of the 3D7 (drug sensitive) and K1 (drug resistant) strains of P. falciparum that possessed significantly reduced ion channel effects and improved metabolic stability. Propafenone analogues are unusual among antimalarial leads in that they are more potent against the multi-drug resistant K1 strain of P. falciparum compared to the 3D7 strain.
We previously reported that substituted 4-aminoquinolines with a phenylether substituent at the 7-position of the quinoline ring and the capability of intramolecular hydrogen bonding between the protonated amine on the side chain and a hydrogen bond acceptor on the amine's alkyl substituents exhibited potent antimalarial activity against the multi-drug resistant strain P. falciparum W2. We employed a parallel synthetic method to generate diaryl ether, biaryl, and alkylaryl 4-aminoquinoline analogs, in the background of a limited number of side chain variations that had previously afforded potent 4-aminoquinolines. All subsets were evaluated for their antimalarial activity against the chloroquine-sensitive strain 3D7 and the chloroquineresistant K1 and cytotoxicity mammalian cell lines. While all three arrays showed good antimalarial activity, only the biaryl-containing subset showed consistently good potency against the drug-resistant K1strain good selectivity with regard to mammalian cytotoxicity. Overall, our data indicate that the biaryl-containing series contains promising candidates for further study.
CPA may complicate ABPA and have distinct radiology features, in addition to bronchiectasis. A novel biomarker is required to anticipate this serious complication, as current serology is not specific enough.
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